1. Field of the Disclosure
The present invention relates to an apparatus for fabricating a light guide panel which can improve light efficiency and brightness, and a backlight unit having the light guide panel.
2. Discussion of the Related Art
In general, as one of flat display devices which displays an image by using liquid crystals, a liquid crystal display device is used widely throughout industries owing to advantages that the liquid crystal display device is thinner, and lighter, and has a lower driving voltage, and a lower power consumption than other display devices.
Since a liquid crystal panel of the liquid crystal display device, which is to display the image, is a non-light emitting device which can not emit a light for the liquid crystal panel itself, the liquid crystal panel requires the backlight unit for supplying the light.
Referring to FIG. 1A, a light guide panel 12 of the backlight unit has an ink pattern 16 printed on a surface. The ink pattern 16 scatters the light totally reflected at, and traveling in, an inside of the light guide panel 12 to emits to an outside of the light guide panel 12, and a reflective sheet 14 or a diffusion sheet scatters or focuses the light for enhancing the brightness of the light. In this instance, since an angle of emission from the light guide panel 12 is 65˜85° which is very large due to a difference of refractive indices between the light guide panel 12 and air, adjustment of the angle is difficult. As shown in FIG. 1B, in order to make the brightness of the light emitted at the large angel higher by converging the light, a light distribution is adjusted such that the brightness is high at a zero degree of the light emission angle by using the diffusion sheet and a prism sheet.
Thus, a related art backlight unit has a problem in that a change of the light distribution dependent on the diffusion sheet and the prism sheet is required due to difficulty of a light emission distribution adjustment only with the light guide panel 12, causing problems of cost increase and total thickness increase of the backlight unit due to provision of the diffusion sheet and the prism sheet.
Moreover, a very low ink pattern 16 of few μm on the related art light guide panel 12 makes the light emission angle adjustment very difficult.